[Diagnosis of malignant hyperthermia. The platelet test versus the in vitro contracture test]

An eight-year-old boy was scheduled for an orthopaedic operation with a clinically abortive reaction of malignant hyperthermia and a positive platelet test result. Since there has been no validation for this platelet test, we performed a muscle biopsy and the caffeine- halothane-contracture test (CHCT). The young patient was found to be negative (MHN) in CHCT. Furthermore, the valence and the validity of the used platelet test are discussed for diagnostic purposes. With regard to resulting consequences, first of all in respect of possibly false negative results, we suggest to investigate all patients classified by this platelet test with the accepted and established CHCT.